{| {{Infobox ship characteristics |Hide header= |Header caption= |Ship type=Nuclear attack submarine |Ship displacement=*Sierra I: 7,200 tons (surfaced) 8,300 tons (submerged) Sierra II: 7,600 tons (surfaced) 9,100 tons (submerged) |Ship length=*Sierra I: Sierra II: |Ship beam=*Sierra I: Sierra II: |Ship height= |Ship draft=*Sierra I: Sierra II: |Ship power= |Ship propulsion=*Sierra I & II: 1 × PWR, 190 MW (HEU <= 45%) 2 × emergency motors 1 shaft, 2 spinners |Ship speed=*Sierra I & II: (surfaced)Sierra I: (submerged)Sierra II: (submerged) |Ship range=Effectively unlimited, except by food supplies |Ship endurance= |Ship test depth= |Ship complement=Sierra I & II: 61 & 72 |Ship sensors= |Ship EW= |Ship armament=*Sierra I & II:2 × torpedo tubes (only Sierra I) 4 × torpedo tubes ( 6 x Sierra II) SS-N-21 Sampson SLCM SS-N-15 Starfish anti-submarine weapon: 200 kt depth charge or 90 kg HE Type 40 torpedo SS-N-16 Stallion, 200 kt depth charge or 90 kg HE Type 40 torpedo Minelaying configuration: 42 mines instead of torpedoes |Ship notes= }} |} The Sierra class, Soviet designations Project 945 Barrakuda and Project 945A Kondor, (NATO reporting names Sierra I and Sierra II' respectively), are a series of nuclear-powered attack submarines intended for the Soviet Navy and currently in service with the Russian Navy. The class is unique due to its light and strong titanium pressure hull which enables the submarines of the class to dive to greater depths, reduce the level of radiated noise and increase resistance to torpedo attacks. It is powered by a single OK-650 pressurized water reactor. The upgraded version, the Sierra II class was specifically developed for search and destroy missions against US nuclear submarines. It has speeds and diving depth greater than its American counterparts at the time it was designed. It has also improved quieting and sonar. Versions Project 945 Barrakuda (Sierra I) The first submarine of the Project 945, Carp, was laid down in July 1979 at the Gorky shipyard and was launched in August 1983 before being transferred to Severodvinsk for fitting out. It was laid up in 1997. The next hull to be built was Kostroma, which was launched in July 1986 and was commissioned in September 1987. K-276 Kostroma was put into a drydock after its 11 February 1992 collision with the US submarine in the Barents Sea, off Kildin Island. The submarine was repaired on 3 June 1992 and was renamed Krab on 6 April 1993,